This invention relates to a method of treating skin disorders caused by transient as well as resident indigenant microorganisms which are present on the outer skin layer or extended downwardly into hair follicles, gland openings, and into the interior of glands.
An antimicrobial is an agent that destroys or inhibits the growth of microorganisms. The major classes of microorganisms are bacteria, fungi including mold and mildew, yeasts, and algae. Microorganisms can be found in the air, the waters, the human body, soil, wastes, and on all surfaces. The organisms are deposited from the air, food and drink spills, dust, dirt and tracked in soil, and from human excreta such as sweat, urine, and feces. Organisms grow and multiply when there is available a nutrient source of food such as dirt, organic or inorganic material, and living tissue. For growth and multiplication, organisms also require warm temperatures, and moisture. When these conditions exist, microorganisms thrive and flourish. Microbial growth, however, leads to many problems such as unpleasant odors ranging from stale to musty and mildew-like, to putrid and foul smelling, resembling ammonia. The growths also produce unsightly stains, discoloration, and deterioration of many surfaces and materials in which they come into contact. A more serious disadvantage of microbial growth is the production of pathogenic microorganisms, germs, their metabolic products and their somatic and reproductive cell parts, which contribute to the spread of disease, infection, and disorders.
Antimicrobial agents are chemical compositions that are used to prevent such microbiological contaminations by inhibiting, killing and/or removing them and neutralizing their effects of deterioration, defacement, odor, disease or other negative effects. Particular areas of application of antimicrobial agents and compositions are, for example, cosmetics, disinfectants, sanitizers, wood preservation, food, animal feed, cooling water, metalworking fluids, hospital and medical uses, plastics and resins, petroleum, pulp and paper, textiles, latex, adhesives, leather and hides, and paint slurries. In the area of medical applications, antimicrobials are often used as powders, in lotions, creams, ointments and/or delivered in a variety of solvents or directly as over-the-counter or ethical drugs to alleviate, mediate, cure and/or protect people or other animals from disease or cosmetic conditions. Of the diverse categories of antimicrobial agents and compositions, quaternary ammonium compounds represent one of the largest of the classes of antimicrobial agents in use. At low concentrations, quaternary ammonium type antimicrobial agents are bacteriostatic, fungistatic, algistatic, sporostatic, and tuberculostatic. At medium concentrations they are bactericidal, fungicidal, algicidal, and viricidal against lipophilic viruses. Silicone quaternary ammonium salt compounds are well known as exemplified by U.S. Pat. No. 3,560,385, issued February 2, 1971, and the use of such compounds as antimicrobial agents is taught, for example, in a wide variety of patents such as U.S. Pat. Nos. 3,730,701, issued May 1, 1973, and 3,817,739, issued June 18, 1974, where the compounds are used to inhibit algae; 3,794,736, issued February 26, 1974, and 3,860,709, issued January 14, 1975, where they are employed for sterilizing or disinfecting a variety of surfaces and instruments; and 3,865,728, issued February 11, 1975, where the compounds are used to treat aquarium filters. Published unexamined European application No. 228,464 of July 15, 1987, teaches that microorganisms on multi-cellular plants can be killed by the application thereto of an aqueous mixture of a surfactant and an organosilicon quaternary ammonium compound. U.S. Pat. No. 4,564,456, issued January 14, 1986, discloses organosilanes as anti-scale agents in water systems. In a particular application of an antimicrobial silicone quaternary ammonium compound, a paper substrate is rendered resistant to the growth of microorganisms in U.S. Pat. No. 4,282,366, issued August 4, 1981. In U.S. Pat. No. 4,504,541, issued March 12, 1985, an antimicrobial fabric is disclosed which is resistant to discoloration and yellowing by treatment of the fabric with a quaternary ammonium base containing an organosilicone. U.S. Pat. No. 4,615,937, issued October 7, 1986, as well as its companion U.S. Pat. No. 4,692,374, issued September 8, 1987, relate to wet wiper towelettes having an antimicrobial agent substantive to the fibers of the web and being an organosilicon quaternary ammonium compound. In a series of Burlington Industries, Inc. U.S. Pat. Nos. 4,408,996, issued October 11, 1983, 4,414,268, issued November 8, 1983, 4,425,372, issued January 10, 1984, and 4,395,454, issued July 26, 1983, such compounds are disclosed to be useful in surgical drapes, dressings, and bandages. This same assignee also discloses these compounds as being employed in surgeons' gowns in U.S. Pat. Nos. 4,411,928, issued October 25, 1983, and 4,467,013, issued August 21, 1984. Organosilicon quaternary ammonium compounds have been employed in carpets, in U.S. Pat. No. 4,371,577, issued February 1, 1983; applied to walls, added to paints, and sprayed into shoes, in U.S. Pat. No. 4,394,378, issued July 19, 1983; formulated as aqueous emulsions in U.S. Pat. No. 4,631,273, issued December 23, 1986; applied to polyethylene surfaces and used in pillow ticking in U.S. Pat. No. 4,721,511, issued January 26, 1988; in flexible polyurethane foams of fine-celled, soft, resilient articles of manufacture in U.S. Pat. No. 4,631,297, issued December 23, 1986; and mixed with a surfactant in British Pat. No. 1,386,876, of March 12, 1975, and in Japanese Kokai Application No. 58-156809, filed August 26, 1983, of Sanyo Chemical Industries, Ltd. Some general, more domestic type applications of these compounds, has included their use in a dentifrice as in U.S. Pat. No. 4,161,518 issued July 17, 1979; in a novel laundry detergent in U.S. Pat. No. 4,557,854, issued December 10, 1985; as a hair conditioner in U.S. Pat. No. 4,567,039, issued January 28, 1986; and in a soft contact lens disinfectant solution in U.S. Pat. No. 4,615,882, issued October 7, 1986. In U.S. Pat. No. 4,614,675, issued September 30, 1986, properties can be influenced by mixing the silicone quaternary ammonium salt compounds with certain siloxanes. Thus, the versatility of such compositions is readily apparent.
The prior art techniques for the treatment of acne have included compositions with an active ingredient such as benzoyl peroxide. Other methods have employed such active ingredients as sulfur, resorcinol, retinoic acid derivatives, and chlorohydroxy-quinoline. In U.S. Pat. No. 4,244,948, issued January 13, 1981, alkyl and aralkyl esters of acetylsalicylic acid are used in a topical acne treatment technique. It is not new to employ silicone compounds in skin treatment. For example, in U.S. Pat. No. 4,515,784, issued May 7, 1985, the spread of skin oil produced in the sebaceous glands is reduced by a composition applied topically that includes a high molecular weight polydimethylsiloxane polymer of molecular weight of about 330,000. Lower molecular weight materials are said to be not significant in the reduction of spreading of the skin oil.
Among the numerous attempts to alleviate the problems of microorganisms on skin surfaces have involved the use of soaps, detergents, and surface cleaners. The treatments, however, have for the most part included an unbound category of antimicrobial which is not actually bonded to the surface sought to be treated, and therefore is consumed by the microorganisms, with the result that the unbound antimicrobial is depleted and washed away during routine cleansing. As this diffusion continues, the concentration of the active ingredient becomes diluted below effective levels, with the result that the microorganisms sought to be inhibited, adapt and build up a tolerance, becoming immune to what was once an effective treatment dose. Such unbound diffusible antimicrobials have therefore been found to be limited in their ability to offer broad spectrum control of microorganisms, in contrast to the bound type of antimicrobial which remains chemically attached to the surface to which it is applied providing for a surface that prevents recolonization by the microflora associated therewith. Diffusing types of antimicrobials also often suffer from the propensity to transfer percutaneously, giving rise to sensitization and irritation immunological responses, and raising serious questions as to their ultimate fate within the body and body systems.
Bound antimicrobials kill organisms on contact and continue to kill organisms without being diffused or leached from the surface. Thus, the bound antimicrobial leaves behind an effective level of active ingredient and is able to control a broad spectrum of microorganisms including gram negative and gram positive bacteria, mold, mildew, fungi, yeast, and algae. An exemplary category of bound antimicrobial is an alkoxysilane quaternary ammonium compound, and such alkoxysilane quaternary ammonium compounds have been found to be more effective at reducing the number of microorganisms, and inhibiting microbially generated odors, than conventional organotin compounds and other organic quaternary ammonium compounds. The silanes of the present invention immobilize on surfaces and bond thereto to provide a coating of immobilized antimicrobial, unlike conventional materials.
In the present invention, this bound characteristic of alkoxysilane quaternary ammonium compounds, as well as their capabilities of performing at effective kill levels beyond prior art types of compositions, is taken advantage of in the treatment of skin disorders, in order to reduce or substantially eliminate the incidence of microorganisms, germs, their metabolic products and their somatic and reproductive cell parts, which contribute to the spread of such disorders.